'SNL's' Taran Killam wrote the script and will make his directorial debut with the ensemble comedy.

Arnold Schwarzenegger is heading back into comedy territory.

The action star will topline Why We’re Killing Gunther, an action comedy that will be directed by Saturday Night Live star Taran Killam, making his directorial debut.

Killam, who also wrote the script, also will star in the ensemble along with his wife, actress Cobie Smulders, SNL’s Bobby Moynihan, Paul Brittain (Hotel Transylvania 2), Kumail Nanjiani (Silicon Valley), Randall Park (The Interview) and Ryan Gaul (Identity Thief).

MadRiver Pictures will introduce the project to international buyers at the upcoming Cannes film market, with UTA representing North American rights.

The story focuses on a group of eccentric international assassins who become fed up with Gunther, the world's greatest hitman who also happens to be an arrogant show-off, and decide to kill him. Their master plan, however, quickly turns into a series of embarrassing encounters as Gunther always appears one step ahead.

A June start date is being eyed.

Killam’s film appearances have included The Heat and 12 Years a Slave. He is repped by UTA, Principato-Young Entertainment and Ziffren Brittenham.

Smulders is best known for starring on TV’s long-running sitcom How I Met Your Mother and for playing agent Maria Hill in various Marvel movies and television shows. She is repped by UTA, ROAR and Gang Tyre.

Schwarzenegger last starred in Terminator Genisys and the zombie drama Maggie. He is repped by CAA and Blooom Hergott.